The headline reads "Study Finds Epigenetics, Not Genetics, Underlies Homosexuality," and the accompanying article goes on to announce, "The study solves the evolutionary riddle of homosexuality," except that it doesn't.
Bold overstatements regarding scientific research about sexual orientation are nothing new, of course. The study in question is actually a review paper that was released in December. It explores existing data that supports the hypothesis that epigenetic factors (essentially, annotations to the genetic code that affect how genes are expressed) play a role in sexual orientation. (A nice explanation of the paper can be found here.) But that hypothesis hasn't even been directly tested yet, much less conclusively established.
Why are some people so quick to latch on to bold claims about the biological origins of homosexuality? I think it's because they believe that we need to show that we're born gay in order to establish that our sexuality is a deep, important and relatively fixed part of who we are. But that's simply not true. Consider a counterexample: My comprehension of English is a deep, important and relatively fixed part of who I am. I could acquire other languages, of course, but none would subsume my native tongue at this point. Being forbidden to express myself in English would be a real deprivation. But I wasn't born comprehending English.
It's also troubling that this paper, like much research in this area, singles out homosexuality as a particular riddle to be solved. It's as if heterosexuality were the default setting, requiring us to figure out "what went wrong" when people turn out gay.
Evolutionary theory holds that we should expect species to reproduce themselves, not that we should expect each individual to do so. There are plenty of features of human evolution that defy explanation when considered in isolation at the individual level (for example, the fact that women live well past menopause).
Personally, I remain agnostic on the question of whether I was born this way; I neither know nor care. I explain why in the video below, one of a series of 11 in the gay-rights debate based on my new book, What's Wrong With Homosexuality?